Technical Field
The present invention relates to pulse tube refrigerators with an improved cooling capability.
Description of Related Art
Pulse tube refrigerators have been known as refrigerators capable of producing low temperatures with reduced vibrations. False tube refrigerators include a compressor, a valve unit, a regenerator, a pulse tube connected to the regenerator, a buffer orifice connected to the pulse tube, and a buffer tank. A refrigerant gas (for example, helium gas) is taken in from and discharged to the regenerator and the pulse tube with predetermined timing.
Cooling is generated at the low-temperature side of the pulse tube by suitably controlling the phase difference between the pressure variation and the displacement of the refrigerant gas inside the pulse tube.